register_balloon() registers the statically allocated balloon device.
When device_register() fails, device_add() drops the reference it took
itself but the reference taken by device_initialize() stays behind, so
the device's private data and name are never released.

Give up that reference with put_device() before unregistering the bus.

Fixes: 803eb047a28d ("xen-balloon: Move core balloon functionality out of module")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/xen/xen-balloon.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index 67b0e2dbe84a..e1db8b2ffc1e 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -256,6 +256,7 @@ static int register_balloon(struct device *dev)
 
 	error = device_register(dev);
 	if (error) {
+		put_device(dev);
 		bus_unregister(&balloon_subsys);
 		return error;
 	}
-- 
2.34.1

On Wed, 04 Nov 2026 02:15:48 +0000, Wentao Liang wrote:
> register_balloon() registers the statically allocated balloon device.
> When device_register() fails, device_add() drops the reference it took
> itself but the reference taken by device_initialize() stays behind, so
> the device's private data and name are never released.
> 
> Give up that reference with put_device() before unregistering the bus.
> 
> Fixes: 803eb047a28d ("xen-balloon: Move core balloon functionality out of module")
> Cc: stable@vger.kernel.org
> Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  drivers/xen/xen-balloon.c | 1 +
>  1 file changed, 1 insertion(+)
> 

Multiple things here:
1. Your team ignored completely previous feedback. Multiple times.

2. You use multiple identities with this email address, thus I doubt that we
   speak with an actual person.

3. Your bot does not even bother running checkpatch, right?

4. Nothing of this was reproduced nor tested.

5. Finally, the same feedback:
You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem (so a patchset grouping multiple patches with a short cover
letter), how to document the issue discovery method and what was
or was not tested.

Best regards,
Krzysztof